In politics, post-primary pivots to the center are common. Outright reversals on key issues are rarer, but they happen. What the Arizona Republican U.S. Senate hopeful, Blake Masters, has pulled off is in a category by itself.

Since winning the GOP primary in early August, Mr. Masters has considerably softened his messaging on everything from the sanctity of the 2020 presidential election to abortion to immigration. Most recently, Mr. Masters scrubbed language from his campaign website claiming that Democrats were trying to import a new electorate to help them win elections, as well as claims that the 2020 presidential election was stolen from President Trump.

He is also walking back some of his “100 percent pro-life” positions, and has softened his push for “a federal personhood law” that would recognize “that unborn babies are human beings that may not be killed.” Now, he is claiming that if elected, he will focus on “getting a ban on partial-birth and third-trimester abortions,” arguing in an interview with KTAR News that “Americans agree we shouldn’t be aborting babies at seven, eight, nine months.”

He’s even recently dulled a rebellious streak during which he said he supported efforts — promoted by Mr. Trump — to remove the Senate minority leader, Mitch McConnell, from his leadership position.

After a McConnell-aligned committee, the Senate Leadership Fund, committed some $14.4 million to his campaign, Mr. Masters began voicing his support for Mr. McConnell.

Despite the maneuvering, Mr. Masters remains behind the Democratic incumbent, Senator Kelly, by an average of about eight points in the polls. While some might blame the poor polling on his new moderate positions, a former mayor of Tucson now teaching political science at University of Arizona, Thomas Volgy, suggests that Mr. Masters’s hardline positions made him a weak candidate to begin with.

Mr. Masters is falling behind “because there has been a consistent attack and publicizing of his extreme positions since he has won the primary,” Mr. Volgy said.

The amount of publicity Mr. Masters has received is why his numbers are lower than those for TV personality Kari Lake, the GOP’s gubernatorial candidate in the state.

Although Mr. Masters has garnered more national attention, the two both received Mr. Trump’s endorsement in the primary and have often appeared together. Before the primary, some speculated that Ms. Lake being on the ticket might weigh down Mr. Masters’s Senate prospects.

Ms. Lake is faring much better against her Democratic opponent, however, with a Trafalgar Group poll showing her statistically tied with the Arizona secretary of state, Katie Hobbs.

“It is clear that independents in the state do not want a Senate candidate with right-wing views, and it is extremely difficult in the short time span between the primary and the election to try to pivot back towards the center,” Mr Volgy said.

Ms. Hobbs and her campaign appear to have drawn the same conclusion as Mr. Volgy. They recently started airing commercials portraying Ms. Lake as an extremist cut from the same cloth as Mr. Masters.

The latest, released on August 25, features clips of Ms. Lake at an event saying, “We know that God did not create us to be equal to men.” The ad then quotes Ms. Lake saying, “You know what? We aren’t equal to men. Women are different to men,” adding: “We don’t want to be equal to them, because we are not the same.” 

Unlike Mr. Masters, Ms. Lake hasn’t backed away from her primary messaging. So far, in fact, she seems to have doubled down.

A few select examples include calls to “fire the federal government,” her description of homelessness as an “alcohol-fueled street lifestyle choice,” and allegations that school boards and teachers unions are “radicals” that are “keeping parents in the dark, spying on them, and labeling them terrorists.”